U.S. markets took a hit as concerns over newly elected Democrats added to fears about AI. Mississippi voters nervously await the result of nail-biter Senate race. And scientists believe they’re on the brink of a new era in Alzheimer’s prevention. Here’s what to know today. Stocks plunge as blue wave and AI worries crush tech sales The Nasdaq and S&P 500 suffered their worst single-day losses since April 2025, when President Donald Trump’s global tariffs sent markets tumbling, with both indexes losing trillions of dollars in value.

The tech-heavy Nasdaq plunged 6.3% yesterday, shedding $2.3 trillion in market value, while the S&P 500 fell 4.4%, losing $2.8 trillion. Asian markets also plunged after they opened Thursday night.

Two lackluster earnings reports on Wednesday night from major chipmakers, Qualcomm and Arm Holdings, triggered the sell-off.

The plunge is partially tied to a blue wave of victories by anti-AI candidates in Tuesday’s midterm elections.

Democrats elected to governorships, attorneys general posts and Congress have pledged to slow or halt AI data center construction.

Tech stocks have surged in recent years as excitement about AI has fueled billions of dollars in investments, but questions about whether it will generate returns on those investments have grown louder in recent months.

Trump blamed Democrats for the market slump in a Truth Social post.

But, he has said little about Republicans’ election losses since Tuesday, insteadg a proclamation yesterday designating the Oval Office and Cabinet Room as a national monument.

Some economists aren’t worried about the stock market dip. Letting some air out of the AI bubble now, they say, could reduce the risk of a full-blown crash later. Read the full story here.

Related coverage: Economists expect the Bureau of Labor Statistics’ October jobs report, set to be released this morning, to show 59,000 added roles, up from September’s 29,000. The unemployment rate is projected to remain at 4.2%. Anticipation and optimism in Mississippi’s nail-biter Senate race The Mississippi Senate race between Democrat Scott Colom and Republican incumbent Cindy Hyde-Smith remained too close to call as of yesterday afternoon.

Colom held a lead of just over 1,700 votes, with only 3,600 ballots left to be counted. If Colom wins, he would not only join the ranks of Democrats who flipped long-red Senate seats, but he’d also become Mississippi’s first Black senator since Reconstruction.

From the grounds of Jackson State University to the halls of the Masonic Lodge which houses the Mississippi State Conference of the NAACP, voters feel that the state may soon reach a turning point. “Hopefully, it’s a sign of a new day, and hopefully people in Mississippi will start looking at policies and issues rather than skin color in deciding who will be their leaders and representatives,” said 75-year-old Carroll Rhodes. NBC News’ Bracey Harris reports from Jackson about the mood in Mississippi.

Colom, however, said he feels like Democrats gave up on voters in Mississippi before the elections were even underway. “Somehow we got in this cycle where they were like, ‘Well, we can’t win, so we’re not going to try,” he said in an interview with NBC News. “First of all, that’s moral — that’s a shame, right?” he said, pointing out that Mississippians have been afflicted by healthcare cuts, tariffs and threats to voting rights. Read more on Colom’s criticism of the Democratic Party.

More election news: City Council member Nithya Raman, a democratic socialist, defeated incumbent Karen Bass in the race for Los Angeles mayor. Harmeet Dhillon, the Republican attorney who oversaw a massive overhaul of the DOJ’s Civil Rights Division that targeted universities and focused on culture war issues, has resigned.

For subscribers: How anger, especially toward Trump’s mass deportation policies, helped fuel Latino voter turnout and a historic Democratic shift in Texas.

For subscribers: Many Republicans leaned into the “culture wars” on the campaign trail. An unlikely critic, Florida Gov. Ron DeSantis, said they were “fighting yesterday’s battle.”

Construction on Trump’s D.C. arch blocked swiftly after approval A federal judge blocked construction of President Donald Trump’s proposed “Triumphal Arch” hours after a planning commission dominated by Trump appointees approved the project. U.S. District Judge Tanya Chutkan granted a temporary restraining order sought by the District of Columbia and Virginia, barring the administration from taking any steps toward the project for 14 days.

The Trump administration had said it expected construction to begin immediately. The National Capital Planning Commission approved the controversial arch in an 8-4 vote, with all four opposing votes cast by commissioners not appointed by Trump. The decision followed more than nine hours of public comments, most of which raised concerns about the arch’s impact on Arlington National Cemetery, as well as its height, scale and safety. Why some lawmakers, veterans and others are opposed to the arch.

More politics news: Defense Secretary Pete Hegseth struck a defiant tone following a renewed impeachment effort against him.

Staff Pick : Are we approaching a new era of Alzheimer’s prevention? Alzheimer’s disease has historically been difficult to detect and even harder to treat. But the past decade has brought remarkable progress, including blood tests that can identify proteins associated with the disease and treatments that help clear them from the brain. Now, scientists believe they’re on the cusp of the next frontier: preventing Alzheimer’s altogether. To shed light on these advancements, our NBC News colleague Sue Kroll opened up about her journey getting tested and treated for early signs of Alzheimer’s in her 50s. After her mother was diagnosed with the disease, Sue noticed that she was struggling to find words or speak in front of groups.

A blood test, followed by a brain scan, confirmed the presence of sticky plaques in her brain that are a hallmark of Alzheimer’s. Sue’s situation is unique, since most Alzheimer’s cases are detected late in life when symptoms are more pronounced. And doctors generally don’t recommend blood tests for people without symptoms, even if they have a family history. To Sue, however, her journey represents a vision for the future: Patients would be screened for Alzheimer’s in their 40s and 50s, then manage their disease through a combination of drugs and lifestyle interventions.

Doctors think that scenario could become a reality in the next 10 years. — Aria Bendix, health reporter Read All About It LIV Golf said its planning to shut down after discussions with a financial backer failed to produce an agreement.

Gov. Gavin Newsom said he plans to commute all 548 death sentences in California, saying he’s opposed to “state-sanctioned killing.”

An infant in Wisconsin died of measles, health officials said, marking the state’s first measles-related death in over 30 years and the U.S.’s third measles-related death reported this week.

Recent ads from Parada, Hermès and Anthropologie have garnered praise for their use of handcrafted art as brands try to separate themselves from AI content. NBC Selected: Online Shopping, Simplified Zombie skin may sound like another TikTok beauty gimmick (or your next Halloween costume), but it’s a real thing that could be impacting your complexion. Plus, can you really erase dark circles? Here’s the truth, according to dermatologists.